It is well known that sudden strobe-like ultra-bright flashes at night time may cause visibility problems for the humans. Such bright lights cause hyper-polarization of the retinal cells in the eye. The hyper-polarized cells take an order of around 2- 3 seconds (time magnitude) to clear the effect. The visibility during this recycle time is challenged. In low-light, and particularly in anxiety and fear, the human eye's iris enlarges to enhance peripheral vision. The enlarged iris further increases sensitivity towards these sudden bright lights that hit the eye, by allowing large exposure values for the retinal cells. As an effect, the iris closes down to bring down the average light to avoid retinal rod/cone damage, thereby reducing the peripheral vision.
In the particular case of automobiles, it is observed that high-beam reach of at least 200 feet is required for vehicle travelling at speeds of 65 mph (or 96.3 ft./sec) to gain reaction time of 1.5 seconds, given the breaking distance of about 50 feet at such a pace. Therefore, intense lights akin to spot lights are required to narrowly focus down the area of lighting to use available energy over a large distance. Such oncoming automobiles' high-beam headlights or extremely bright spots may cause the problem with driver's visibility in the vehicle ahead. At this stage, the shadowy regions of the scene get blocked out due to automatic control of overall exposure, thereby reducing any information available in the low-light zones. The loss of detail increases anxiety and fear, further increasing adrenalin which in turn tries to widen the closed-down iris to enhance peripheral vision in futility. This oscillatory (albeit negatively) reinforcing feedback loop results in high-stress and is caused by lack of visibility of details in the shadows. This is akin to panic attack situation and could result in accidents. This demonstrates a need for a device to avoid loss of visibility from oncoming headlights or the like.
The systems and methods known in the art approach this problem by using photosensitive materials, such as, electro-chromic glass, using chemical means to achieve dimming of bright lights passed through. Such system averages the light intensity on the entire viewing surface, and therefore results in poor detail in the shadows. Therefore, there is a need of a device which may help to reduce glare without loss of any details. The system of the present disclosure enables to spatially and selectively process the incoming light for reducing glare, and thus provide better control over the visibility over the viewing surface.
US Patent Publication Number 20060140502 discloses a field-of-vision processing and filtering system for eliminating glare from mobile and transient light sources and reflective surfaces, using image recording, eye-position detection, and an active matrix screen functioning as a dynamically controllable visor, for modifying the field of vision appropriately. One embodiment of the system can be used by drivers for filtering glare from oncoming headlight at night, as well as during day time to block glare from the sun. The system uses multiple cameras placed appropriately to record the driver's field-of-vision. The system then filters out high light intensity points from the field-of-vision using digital processing employing some algorithms. The end image is displayed by computing the field-of-view of the driver's eye and producing the appropriate camera feed, after processing, on the display. The system disclosed is an image processing device to digitally compute the translational and rotational movement of the driver's face, and requires elaborate computation with demanding response times of the order of say 30 Hz on the part of the computer to compute the position of the blocking. To complicate this further, the opposing bright lights from automobiles constantly moves position as well when they are close to the driver. So, the system requires high computation power and therefore would involve expensive components. In addition, there may be heavy parallax error between left and right eyes of the driver.
Another US Patent Publication Number 20060055713 discloses an ECB-type (Electrically Controlled Birefringence effect type) liquid crystal display element. The display utilize a birefringent action of a liquid crystal and a polarization action, in which absorption of light by a color filter does not occur, and therefore the light transmittance can be increased to obtain bright color display. In addition, since birefringent characteristics of a liquid crystal layer vary depending on voltages, the colors of transmitted light and/or reflected light may be changed by controlling the voltage applied to a liquid crystal cell. By utilizing this, a plurality of colors can be displayed with the same pixel. The purpose of this invention is to improve the brightness of the displayed colors by removing the color filter, and avoiding the color loss thereon. However in the mode of transmission, such system only relates to color rendition.